President Obama has been enjoying himself on the campaign trail. Now he's getting downright slap-happy. In a bit of nonverbal communication that speaks volumes, the president has been punctuating his campaign rallies for Democratic presidential nominee Hillary Clinton by slapping the side of the lectern several times. We know the road to the White House is paved with hard knocks. But we didn't know it was meant so literally. Turns out, Obama has been doing this since at least 2012, per video evidence on YouTube. And aides said they recall him doing it as far back as 2007, when he made his first run for the presidency.